Method and device for activating passenger protection device

Abstract

In a method and apparatus for activating vehicle-occupant protection devices, an approach speed to a collision object is determined within a predefined proximity range of the vehicle surroundings. If the approach speed is above a threshold value, an anticipated impact time for a collision with the object is determined. A time range is determined on the basis of the anticipated impact time, a signal quality of at least one proximity sensor, driving dynamics and the geometry of a collision object being taken into account in this time range. The assigned vehicle-occupant protection devices are activated after occurrence of a positive plausible-confirmation check within the time range.

1. A method for activating a vehicle-occupant protection device, said method comprising:
 determining an approach speed relative to a collision object that is within a predefined proximity range of the vehicle;  
 if the approach speed is above a threshold value, determining an anticipated impact time for a collision with the object;  
 determining a time range based on the anticipated impact time, and taking into account signal quality of at least one proximity sensor, driving dynamics and geometry of a collision object; and  
 activating the vehicle-occupant protection devices after occurrence of a positive plausibility-confirmation check within the time range.  
 
     
     
       2. The method as claimed in  claim 1 , wherein a lower limit of the time range takes into account signal quality of the proximity sensor and geometry of the collision object. 
     
     
       3. The method as claimed in  claim 1 , wherein an upper limit of the time range takes into account signal quality of the proximity sensor and driving dynamics of the vehicle. 
     
     
       4. The method according to  claim 1 , wherein, for plausibility-confirmation checking, one of an acceleration signal and a signal which is equivalent to an acceleration signal is checked to determine whether it is above a predefined threshold and whether it corresponds in terms of its sign to an impact direction determined by the at least one proximity sensor. 
     
     
       5. The method according to  claim 4 , wherein the acceleration signal is determined by means of at least one acceleration sensor. 
     
     
       6. A device for activating a vehicle-occupant protection device, comprising:
 at least one proximity sensor for determining an approach speed to a collision object within a predefined proximity of the vehicle; and  
 a computer unit programmed to determine an anticipated impact time if the approach speed is above a threshold value;  
 determine a time range on the basis of the anticipated impact time, as a function of signal quality of the at least one proximity sensor, driving dynamics of the vehicle and geometry of the collision object; and  
 activate an assigned vehicle-occupant protection device after a positive plausibility-confirmation check within the time range.  
 
     
     
       7. The device according to  claim 6 , wherein the at least one proximity sensor comprises at least one internal pressure sensor in a vehicle door. 
     
     
       8. The device according to  claim 6 , wherein in each case two proximity sensors and an acceleration sensor are provided in a front region and in a side region of the vehicle and in addition a further acceleration sensor is provided in an airbag controller. 
     
     
       9. A method for triggering a vehicle occupant system in a vehicle having an acceleration sensor for detecting a collision of the vehicle with an object when an acceleration of the vehicle exceeds a preset value, said method comprising:
 determining a time window within which a collision may occur, based on proximity and approach parameter values for an object;  
 triggering said vehicle occupant protection system if an acceleration of the vehicle exceeds said preset value during said time window.  
 
     
     
       10. The method according to  claim 9 , wherein said determining of said time window is based on a determined theoretical collision time, and at least one of a signal quality of a proximity sensor which detects said object, driving dynamics of the vehicle and geometry of the object. 
     
     
       11. The method as claimed in  claim 10 , wherein a lower limit of the time range takes into account signal quality of the proximity sensor and geometry of the collision object. 
     
     
       12. The method as claimed in  claim 10 , wherein an upper limit of the time range takes into account signal quality of the proximity sensor and driving dynamics of the vehicle. 
     
     
       13. The method as claimed in  claim 11 , wherein an upper limit of the time range takes into account signal quality of the proximity sensor and driving dynamics of the vehicle.